scholarly journals Measurements of 1H and 2H NMR Spectra for Water Molecules Sorbed into Polymers.

1996 ◽  
Vol 53 (5) ◽  
pp. 308-310 ◽  
Author(s):  
Hiroshi KUSANAGI ◽  
Kenji MATSUMURA
Keyword(s):  
Nmr Spectra ◽  
Water Molecules ◽  
2H Nmr

scholarly journals Study of Structural Phase Transitions in [Mg(H2O)6][SiF6] by Means of Single Crystal 2H NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 408-412 ◽  
Author(s):  
Takahiro Iijima ◽  
Motohiro Mizuno ◽  
Masahiko Suhara ◽  
Kazunaka Endo
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Nmr Spectra ◽  
Structural Phase ◽  
Water Molecules ◽  
2H Nmr ◽  
Structural Phase Transitions ◽  
H Nmr ◽  
Rotational Modulation ◽  
Infinite Temperature

The temperature and angular dependences of 2H NMR spectra were measured for single crystal of [Mg(H2O)6][SiF6]. At 283 K, (e2Qq/h,η) of 2H, averaged by fast 180° flip of water molecules, were obtained as (128 kHz, 0.72), (123 kHz, 0.82) and (106 kHz, 0.80), corresponding to three unequal water molecules in [Mg(H2O)6]2+. At 338 K, (e2Qq/h,η) averaged further by the fast reorientation of [Mg(H2O)6]2+ around the 3 axis was obtained as (57 kHz, 0.01). In phase II, the jumping rate for the reorientation ( ) and the amplitude of the rotational modulation (Δ ) of [Mg(H2O)6]2+ about the C3 axis were obtained from the simulation of 2H NMR spectra. The jumping rate at infinite temperature and the activation energy were estimated from the temperature dependence of k as k0 = 9 1017 s-1 and a = 78 kJmol-1, respectively. The II-III phase transition was found to be related with the freeze of this motion

Deuterium Quadrupolar Parameters from 1H and 2H NMR Spectra for Pyridine-d5, Benzonitrile-d5 and Chlorobenzene-d5 Using Liquid Crystal Solvents

1986 ◽  
Vol 41 (1-2) ◽  
pp. 431-435 ◽  
Author(s):  
R. Ambrosetti ◽  
D. Catalano ◽  
C. Forte ◽  
C. A. Veracini
Keyword(s):  
Liquid Crystal ◽  
Nmr Spectra ◽  
Order Parameters ◽  
Dipolar Couplings ◽  
Coupling Constants ◽  
2H Nmr ◽  
H Nmr ◽  
Quadrupolar Coupling ◽  
Asymmetry Parameters ◽  
Quadrupolar Splittings

T he quadrupolar coupling constants (DQCC) and the asymmetry parameters (η) for the ortho, meta and para deuterons in pyridine-d5, benzonitrile-d5 and chlorobenzene-d5 were determined by NMR spectroscopy in oriented phases. The 1H and 2H NMR spectra were recorded in the following solutions in liquid crystal solvents: pyridine + pyridine-d5 in PCH , in ZLI 1167 and in EBBA; benzonitrile + benzonitrile-d5 and chlorobenzene + chlorobenzene-d5 in the same solvents.The order parameters of the non-deuterated solutes in the various solutions were calculated using the dipolar couplings of the proton spectra and the rα structures taken from the literature. The same order parameters were assumed to describe also the orientation of the deuterated solute in the corresponding solutions.Each 2H spectrum yielded three quadrupolar splittings for the three different deuterated positions in the labelled solute. The splittings from the three different solutions of the same solute, together with the order parameters and the rα structure, were used to determine DQCC and η of the ortho, meta and para deuterons (Pyridine-d5: DQCCortho= 183(1) kHz, ηortho = 0.030(5), DQCCmeta = 185(1) kHz, ηmeta = 0.030(10), DQCCpara = 188(6) kHz, ηpara = 0.01(5). Benzonitrile-d5: DQCCortho = 171(12) kHz, ηortho = 0.07(3), DQCCmeta = 175(12) kHz, ηmeta = 0.05(3), DQCCpara = 176(4) kHz, ηpara = 0.10(7). Chlorobenzene-d5: DQCCortho = 180(2) kHz, ηortho = 0.06(1), DQCCmeta = 174(2) kHz, ηmeta = 0.09(3), DQCCpara= 182(4) kHz, ηPara = 0.06(4)). The results are discussed, as well as the limits and possibilities of the method used.

Multiaxial Reorientationsof ND+4 Ions Studied by 2H-NMR Spectroscopy

1991 ◽  
Vol 46 (10) ◽  
pp. 829-840 ◽  
Author(s):  
Z. T. Lalowicz ◽  
S. F. Sagnowski
Keyword(s):  
Nmr Spectroscopy ◽  
Density Matrix ◽  
Nmr Spectra ◽  
Activation Energies ◽  
Matrix Formalism ◽  
2H Nmr ◽  
Jump Frequency ◽  
H Nmr ◽  
2H Nmr Spectroscopy ◽  
Density Matrix Formalism

AbstractThe density matrix formalism is used to simulate motional averaging in the 2H-NMR spectra of reorienting ND+4 ions. The development of the spectra under increasing jump frequency about a single C3 or C2 axis is followed. Next we assume a hierarchy of axes in terms of activation energies sufficient to reach extreme narrowing conditions for some axes before activating jumps about a next one. Primary reorientations about the fastest C3 or C2 symmetry axes define the shape of spectra, the width of which is then stepwise reduced by fast reorientations about the subsequent axes in a postulated sequence of statistically uncorrelated jumps.

2H and 195 Pt NMR Studies of Molecular and Electron Spin Dynamics in Paramagnetic [Cu(H2O)6][PtCl 6]

1998 ◽  
Vol 53 (6-7) ◽  
pp. 447-452
Author(s):  
Takahiro Iijima ◽  
Kengo Orii ◽  
Motohiro Mizuno ◽  
Masahiko Suhara
Keyword(s):  
Activation Energy ◽  
Electron Spin ◽  
Nmr Spectra ◽  
Chemical Shift Anisotropy ◽  
Spin Lattice Relaxation ◽  
Water Molecules ◽  
Temperature Phase ◽  
Nmr Studies ◽  
Teller Distortion ◽  
Exponential Factor

Abstract The temperature dependences of 2H and 195Pt NMR spectra and the spin-lattice relaxation time T1 were measured for [Cu(H2O)6][PtCl6]. From the simulation of 2H NMR spectra, the jump rate of 180° flips of the water molecules (k), the nuclear quadrupole interaction parameters (e2Qq/h, ƞ) and the electron-nucleon dipolar interaction parameter (vD) were obtained. By measuring 2H T1, k was estimated in the temperature range where the spectrum is insensitive to the motion of the water molecules. Above the phase transition temperature, the pre-exponential factor k0 = 8 x1011 s-1 and the activation energy Ea = 15 kJmol-1 for 180° flips of the water molecules were obtained from the spectral simulation and T1. 195Pt NMR spectra showed an axially symmetric and unsymmetric powder pattern of the chemical shift anisotropy at the high and low temperature phase, respectively. For the deuterated compound, the correlation times of the electron spin in Cu2+ were estimated from 195Pt T1 and the activation energy for jumping between the different configurations of Jahn-Teller distortion Δ = 200 K was obtained.

2H NMR spectra of trimethylsilyl groups anchored on a silica surface

1986 ◽  
Vol 173 (2-3) ◽  
pp. L655-L658
Author(s):  
B. Boddenberg ◽  
R. Grosse ◽  
U. Breuninger
Keyword(s):  
Nmr Spectra ◽  
Silica Surface ◽  
2H Nmr ◽  
Trimethylsilyl Groups

Angular dependence of 1H- and 2H-NMR spectra of H2O and D2O absorbed in cellulose acetate film

1987 ◽  
Vol 25 (10) ◽  
pp. 2149-2163 ◽  
Author(s):  
Kazunori Matsumura ◽  
Kikuko Hayamizu ◽  
Takashi Nakane ◽  
Hiroshi Yanagishita ◽  
Osamu Yamamoto
Keyword(s):  
Cellulose Acetate ◽  
Angular Dependence ◽  
Nmr Spectra ◽  
2H Nmr ◽  
Cellulose Acetate Film
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